植物铜素毒害及其抗性机制研究进展

Mechanisms of copper toxicity and resistance of plants

Cu是植物生命活动必需的微量矿质元素,广泛参与各种生命活动;但过量Cu胁迫将诱导植物细胞产生大量活性氧,引起膜脂过氧化,膜透性增大,细胞内容物大量外渗,甚至发生细胞死亡。Cu2+扩散到细胞核内会诱发DNA之间、蛋白质之间以及DNA和蛋白质之间发生分子内和分子间交联,DNA链的断裂、重排和脱嘌呤作用等前诱变损伤以及DNA期外合成、DNA甲基化异常等遗传毒害。植物细胞在长期进化过程中形成了各种抗Cu素毒害机制,如细胞壁的固着作用、质膜的限制作用、有机小分子(有机酸、植物螯合肽、金属硫蛋白)螯合作用等。文章综述了有关研究的最新进展。

Copper is an essential nutrient element of plants, playing an important role in the metabolism of plants. However, excessive copper in the cell induced a generation of all sorts of reactive oxygen species which cause subsepuent propagation of chain reactions and oxidative stress. Furthermore, the part of copper binding to the cell nucleus lead to promutagenic damage including DNA base modifications, inter- and intramolecular crosslinking of DNA and proteins, DNA strand breaks, rearrangements and depurination, and DNA methylation aberration. Plant cell developed various defense mechanisms to combat the copper toxicity including the immobilization of the cell wall, the limitation of cell membrane and the chelation of glutathion-derived peptides named phytochelatins and metallothioneins .The paper discussed the newest advance in the field.